下列关于公司财务会计的说法正确的是：A．《公司法》规定公司有提取法定公益金的义务 B

热水供暖系统按（）的不同．可分为自然循环系统和机械循环系统。

A、散热设备

B、循环动力

C、热媒

D、热源

电空控制器重联位时，有（）个电空阀得电。

A、1

B、2

C、3

D、4

DOM is a platform-and language- (1) API that allows programs and scripts to dynamically access and update the content, structure and style of WWW documents (currently, definitions for HTML and XML documents are part of the specification). The document can be further processed and the results of that processing can be incorporated back into the presented (2) DOM is a (3) -based API to documents, which requires the whole document to be represented in (4) while processing it. A simpler alternative to DOM is the event-based SAX, which can be used to process very large (5) documents that do not fit into the memory available for processing.

(3)

A．table

B．tree

C．control

D．event

超文本的主要成分包括（）。

A.结点

B.链

C.宏结点

D.以上选项都对

RVSM飞行前，检查高度表的误差应不超过以下哪个标准？（）

A.高度表指示的机场标高和已知的机场标高的差值不超过75英尺

B.左右座高度表指示的差值不超过75英尺

C.高度表指示的机场标高和已知的机场标高的插值不超过50英尺

D.左右座高度表指示的差值不超过50英尺